Pyrometric cone plaque



Feb. 24, 1942.

H. S. ORTH ETAL PYROMETRIC CONE PLAQUE Filed April 5, 1940 Patented Feb. 24, 1942 PYROMETRIC CONE PLAQUE Howard S. Orth, Clair R. Oberst, and William E. Cramer, Columbus, Ohio, assignors to Industrial CeramicProducts, Inc., Columbus, Ohio, a corporation of Ohio Application April'3, 1940, Serial No. 327,688

6 Claims.

This invention relates generally to the ceramic industry and is particularly directed to a plaque for holding pyrometric cones employed in the industry to determine the temperatures of kilns during ware firing operations.

In most instances, when it is desired to use pyrometric cones, the kiln operators prepare plaques, for holding the cones, from soft clay or other ceramic material by manual operations. The cones are then pressed into the soft plaques and the clay pinched or squeezed around the base portions of the cones to make them stand upright. It has been found that in order to give a true indication of the temperature of the kiln, the cones should be inclined or made to lean to a predetermined degree, namely 82 degrees, with respect to a horizontal plane. When the cones are positioned in a relatively plastic hand made plaque in the manner'set forth, the degree at which the cones are inclined is left entirely to the skill of the operator with the result that uniform firing temperatures over a period of time cannot be secured even with cones having the same characteristics.

The primary object of this invention resides in the provision of pyrometric cone holding means which will be preformed and hardened to such an extent that the shape will be maintained during ordinary handling, the holding means being provided with sockets for the reception of the cones, which sockets are so formedas to cause the cones to incline or lean in the desired direction to a predetermined degree.

Another object resides in providing a pyrometric cone holding plaque which is formed for the reception of a plurality of cones, the cone receiving means being constructed in such manner as to cause each of the cones held thereby to lean in the same direction and to the same extent. A still further object resides in the provision.

of a cone plaque formed from a ceramic material possessing the same characteristics as the material from which the cones are formed to the end.

that when the cones are positioned in the plaque and subjected to the heat of the kiln, the cones and plaque will shrink uniformly and the former will thus be firmly held at all times.

Another object resides in providing a slab-like ceramic body having cone receiving openings extending therethrough from the upper to the lower surface, the sides of the openings being inclined to cause the openings to be larger at the lower surface than at the upper surface whereby the cones may be inserted from the under side of the body and forcibly urged into place, the inclination of the side walls serving to grip the cones and positively maintain them in their predetermined positions.

Other objects will be apparent from the following description and the accompanying drawing in which the invention has been illustrated in one of its simple preferred forms.

In the drawing:

Fig. 1 is a perspective View of a plaque formed in accordance with the present invention;

Fig. 2 is an elevational view of the plaque taken from the under side;

Fig. 3 is a vertical longitudinal sectional view taken through the plaque on the plane indicated by the line III-III of Fig. 2;

Fig. 4 is a vertical transverse sectional view taken on the plane indicated by the line IVIV of Fig. 3;

Fig. 5 is a perspective view of the plaque having pyrometric cones positioned therein.

Referring more particularly to the drawing, the numeral I designates the plaque in its entirety. This plaque comprises a body 2 which is formed from clay or other ceramic material of the type used in the manufacture of pyrometric cones. The body is, in this instance, of rectangular configuration when viewed in plan and has a slab-like form in that it is relatively thick. The body 2 is provided with longitudinally spaced openings 3 of triangular configuration which openings are adapted for the reception of pyrometric cones. Such cones are usually of triangular pyramidal form, thus requiring the openings to be of the same horizontal cross section;

It is, of course, within the concept of the invention to change the shape of the openings in the event a different shape should be given to the cones to be held in the plaque.

It has been found that to give the proper indication, pyrometric cones should be inclined 8 degrees with respect to the vertical in order that when they-become softened by the heat of the kiln, they will .bend in the proper direction. To provide for the inclination of the cones, the openings 3 have their longitudinal axes inclined with respect to the under surface of the body 2. One side of the openings, designated by the numeral 4 and termed the front of the openings, extends transversely of the body and is slightly inclined to correspond to the front surface of the cone to be positioned in the opening. The rear walls of the openings are undercut and are inclined to a slightly greater degree than the walls of the cone with which the walls of the opening are to be engaged. This arrangement provides a tapered socket which receives the base portion.

of the cone and, due to the greater inclination of the rear walls, as indicated by the angle X, the sockets will exert a gripping action on the cone when pressure is applied to the base after the cone has been inserted in the plaque from the under side.

By forming the body of material having the same characteristics as the material from which the cones are formed, the same degree of shrinkage will be maintained and the relative size of the openings and the cone bases will be maintained in order that when the plaque and cones are subjected to the heat of the kiln, the shrinkage will be uniform and the cones firmly held in an upright position. After the body has been formed, it is air dried or subjected to a moderate heat to expel the moisture, after which it will be substantially rigid and able to withstand ordinary handling without breakage.

The plaques may be made of various sizes and provided with any number of sockets depending upon the desires of the manufacturer, or it may be found desirable to produce the bodies in predetermined lengths having a multiplicity of sockets and transversely extending weakened portions 5 between adjacent sockets. These weakened portions may be provided by producing registering grooves 6 in the upper and lower surfaces of the body. By the provision of the grooves, the body may be broken into plaquesections having one or more sockets depending upon-the use to which they are to be placed.

While the drawing shows the body with V- shaped grooves 6 in both upper and lower surfaces, it is obvious that the shape of the grooves could be modified and the grooves may be formed only in one surface or omitted entirely.

By inclining the sockets, the same degree of inclination of the cones may be secured at all times even when the cones are positioned within the plaques by relatively unskilled workmen.

It has been found in actual practice that most commercial cones possess an irregular shape at 2 the base end by reason of inaccuracy or careless production. Therefore, in order to adapt the plaque to such cones, the lower ends of the sockets 3 are varied slightly from a true triangular form by curving the sides 3a to a limited extent and rounding the corner 3b between these sides. By thus forming the sockets with a semiegg-shaped cross section as the lower end, commercial cones may be positioned and held therein without any looseness.

In most instances, pyrometric cones are each provided with a mark to inform the user of the fusible characteristics thereof. These marks are impressed in the front surface near the lower end portion and when the cones are disposed in the sockets of a plaque in use, the mark will be visible above the upper surface of the plaque. Sometimes the marks are placed nearer the lower ends of the cones and in such cases or when larger cones are employed, the marks may be disposed slightly below the upper surface of the plaque. To render the marks visible in such instances, the front walls 4 of the sockets have a notch 4a formed therein at the central portions. It is, of course, obvious that if the cones are carefully formed and the identification marks correctly located, the sockets may be made to conform more accurately to the shape of the cones and the notches omitted.

While but a single embodiment of the invention has been illustrated, it is obvious that many minor changes may be made in the shape of the body and the relation of the sockets without departing from the spirit and scope of the invention as set forth in the following claims.

What is claimed is:

1. A pyrometric cone plaque comprising a substantially rigid ceramic body of slab-like form, said body being provided with a plurality of triangular openings extending therethrough from top tobottom, said openings being larger in size at the bottom than at the top of said body, the longitudinal axes of said openings being disposed at a predetermined angle other than ninety degrees with respect to the lower surface of said body.

2. A pyrometric cone plaque comprising a substantially rigid ceramic body of slab-like form, said body being provided with a plurality of openings extending therethrough from top to bottom, each opening having an inclined front wall and a pair of angularly related undercut rear walls, said rear walls being inclined to a greater degree than said front wall.

' 3. A plaque for holding pyrometric cones comprising a substantially rigid slab-like body formed from ceramic material having characteristics similar to the material from which the cones to be held are formed, said body having a plurality of openings extending therethrough from top to bottom, the longitudinal axes of said openings being inclined with respect to the vertical, said openings being shaped to exert a gripping action on the base portions of pyrometric cones inserted therein upon the application of pressure to the under sides of said cones.

4:. A pyrometric cone plaque comprising a substantially rigid ceramic body of slab-like form, said body being provided with spaced openings extending therethrough from top to bottom, each opening having a forwardly inclined flat front wall and a pair of slightly curved rear walls, said rear Walls being undercut and inclined to a greater degree than the forward wall, the curvature of the rear walls giving the openings a substantially semi-egg-shaped horizontal cross section at the lower end.

5. A plaque for holding pyrometric cones of the type having inclined rear corner edges, a rigid ceramic body of slab-like form having a plurality of openings extending therethrough from top to bottom, each openings having a genral contour and size to correspond to the contour and size of the cone portion intended to be positioned therein, the rear corners of said openings being inclined to a slightly greater extent than the rear corner edges of the cones to cause gripping forces to be exerted on said cones when the same are forced into said openings.

6. A pyrometric cone plaque comprising a substantially rigid ceramic body having a plurality of openings extending therethrough for the reception of the base portions of pyrometric cones having similar structural characteristics, said openings extending through said body at an angle other than degrees with respect to the bottom surface of said body to cause cones positioned therein to lean in a predetermined direction when said body is resting on its bottom surface, the angular relation of the openings being equal, said body being provided with transversely extending weakened regions between adjacent openings whereby the body may be separated into a plurality of sections.

HOWARD S. ORTH. CLAIR. R. OBERST. WILLIAM E. CRAMER. 

